Archive for the ‘PCB News’ Category

How to choose surface finish on Printed Circuit Board?

Saturday, December 17th, 2022

When finish the PCB design, we should choose a suitable surface finish to protect traces from corrosion. Nowadays, the most popular surface treatments for PCB manufacturer to use are HASL/LF HASL, OSP and ENIG.

Different surface treatment has its unique functionality and the cost also is different. This article we will show you the pros and cons of the three surface finishing which use while the PCB manufacturing process.

HASL Surface Finish

HASL (Hot Air Solder Level) can be known as tin-lead HASL and lead-free HASL, it was the mainstream surface treatment technology in the 1980s, but with the increased of “small and high density” demands in PCB, there are less and less circuit boards use the HASL technology because it will cause the defective products due to the solder point are easy to leave on the board surface during SMT process. In view of this situation, some PCB board manufacturers or designers prefer use OSP or immersion gold to ensure the good quality products as well as smooth production process.

  • Tin-lead HASL

Advantages:

1) Economical and widely available.

2) Excellent solderability.

3)Better mechanical strength & lustrousness than lead-free HSAL.

Disadvantages: it is harmful to environment and violates RoHS compliance.

  • Lead-free HASL

Advantages: low cost, good solder performance and environmental.

Disadvantages: mechanical strength & lustrousness are not good than lead HASL.

In additional, due to the poor surface flatness of HASL circuit boards, neither leaded nor lead-free HASL is not suitable for soldering fine-pitch components or plated through-holes, because it will cause the short circuits and poor welding during the assembly process.

(LF_HASL)

OSP

OSP (Organic Solderability Preservatives) also named as pre flux, the working principle is to generate a layer of organic film chemically on the copper surface to protect the surface from oxidation or vulcanization in the room environment. Meanwhile, OSP also can increase the oxidation resistance, heat shock resistance and moisture resistance of a PCB. 

OSP is equivalent to an anti-oxidation treatment, the protective thin film can be easily removed by the flux quickly under the high soldering temperature, then it makes the exposed copper surface immediately combined with the molten solder in a very short time to become a solid solder spot.

At present, the usage of OSP surface finishing process has increased significantly because it is appropriated for both low and high-end products. If your application has no surface connection functional requirements or storage life limitations, the OSP process is the most desirable surface treatment process.

(OSP_surface_treatment)

Advantage:

1)With all the advantages of bare copper soldering, expired (more than 3 months) boards can also be resurfaced, but one time is better.

2)Good for fine-pitch, BGA and smaller components.

3)Low cost and easy to rework.

4)Simple process and easy to ensure quality.

Disadvantage:

1)OSP is easily affected by acid and humidity, so must be packed with vacuum.

2)Need to do surface treatment again if storage time more than 3 months.

3)It should be used within 24 hours after unpacking.

4)OSP is an insulating layer, so the test point must be printed with solder paste to remove the original OSP layer for electrical testing.

ENIG

ENIG (Electroless Nickel/Immersion Gold) is one of a chemical nickel gold deposition method, the working principle is to generate a layer of coating by chemical REDOX reaction to get a thicker gold layer. Currently, ENIG is mainly used in the surface of the circuit board with connection functional requirements and long storage life.

Advantage:

1)Can be stored long time as well as no oxidation.

2)Good flatness surface and suitable for small solder point components.

3)Good solderability.

4)Can be used as the base material for COB wire bonding.

Disadvantage:

1)High cost than other two surface treatments.

2)Easy to exist black-pad issue during production process.

(ENIG)

As we can know from above information, each PCB surface treatment has its own merit and demerit, you can choose the one according to the effect you want to reach, as well as your cost. 

If you don’t know which is best for you, you can send inquiry to us, our professional engineering team and PCB sales will choose the suitable one for you. Welcome to contact us if you have any other questions.

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How To Make PCB Silkscreen on Automatic Silkscreen Printer

Thursday, December 8th, 2022

If you’ve ever learned a printed circuit board, you may see some silkscreen legends printed on the PCB. Silkscreen legend plays an important role in PCB production process.  Therefore, the quality of silkscreen also is significant.

(Silkscreen)

Last time we share some acknowledges about silkscreen guideline, today we will introduce how to make PCB silkscreen on the Automatic Silkscreen Printer step by step for you.

Manufacturing processes of printing silkscreen

  • Screen fix

Step 1, we need to fix the screen on the base or workbench with a fixture, and leave 3-5mm distance away from the positioning plate when put the screen.

  • Align and position

Step 2, we need to place the circuit board on the positioning plate with right-angle positioning method or stud registration method (generally use 2 positioning pieces), make it fixed and aligned, then put down the stencil frame and adjust the positioning button, so that the PCB outline is roughly overlapping with screen. Next step, perform initial align boards according to the positioning holes or outline line, then gradually adjust to the optimal position based on pads.

  • Silkscreen ink selection and fine-tune

Step 3, we need to select the silkscreen ink according to the customer requirements, put down the screen frame and poured ink into the screen frame, and then select the length of the appropriate scraper for trial printing sample, and fine-tune the positioning until accurate. 

  • Trial printing

Step 4, we will need to do trial printing the prototypes with transparent character alignment film and check to see if there is a legend deviation, if no, then we can proceed with mass production, but if not, then the positioning should be fine-tuned again, rip off the defective film and affixed with the new one then printing again, repeat trail until qualified.

(Trail_printing_inspection)
  • Screen printing (manually)

Step 5, let’s place the circuit board (which have finished surface treatment process) on a fixed position, put down the screen frame, and then hold the scraper with both hands, at an Angle of 50°- 60 ° with even force on the scraping screen surface from front to back or from back to front. The printing material is subjected to the pressure of the scraper through the printing mesh hole and printed on the circuit board. After the scraper passes through, the screen recovers by its own tension. After the scraper is finished, the screen frame is lifted, and the sealing screen printing material is scraped back.

  • Screen printing (auto printer)

Step 6, the Angle of the scraper is an external “eight” font, usually between 20-30 degrees, you can choose the printing times according to the actual needs.

(Auto_printing)

In the past, most of the factories make the screen printing manually, it is time consuming and limited to relatively short lengths of 60 yards. So, in our manufacturing line, we have imported the automatic flat-bed screen printing.

Automatic_Silkscreen_Printer

Here I would like to share some features of the PCB silkscreen printer with you:

Features of Auto-Printer

  • High speed: the automatic screen printer has its own unique frequency conversion speed regulation device, the printing speed can be adjusted from 20 to 70 times per minute auto screen printing machine.
  • Cost-effective: the auto printer has its own electronic counter, which can automatically shut down according to the pre-designed total number, saving a lot of manpower and ink material.
  • Good quality: the automatic screen printer is very accurate in point and color, because it is equipped with a multi-color printing electric eye device, which can improve the quality of printing.
  • Good adhesive: the adhesion of the screen machine is very good, and the ink layer is relatively thick, so the text legend is not easy to fade.
  • Multi-aspect: the fully automatic screen printer can not only be used alone, but also can be connected to a UV dryer, or a slitting machine, a reminder, and other auxiliary machines.

With the help of Automatic silkscreen printer, we are able to provide “faster” and more “efficient” service to our customers, warmly welcome to contact us, we are ONLINE always!

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Differences Between Solder Mask and Solder Paste in PCB

Wednesday, December 7th, 2022

When it comes to solder mask and solder paste, there are some engineers confused about their functionalities and even most of laymen thought they are the same, this is not hypothetical, it is real that happened to me. So today let’s explain differences between Solder Mask and Solder Paste for you.

Part 1: What is Solder Mask?

If you had ever seen a printed circuit board, you may see there is a layer of green ink cover on the PCB surface while some orange-yellow areas didn’t cover by ink. In PCB industry, the green ink we called Solder Mask, or abbreviated as S/M, and exposed area is copper, they were leave as GND plane or soldering pads to mount electronic components.

Solder mask is a liquid acrylic oligomer, which has variety of colors such as red, blue, green, white, black. Green is commonly used in the process of PCB manufacturing, so some professional engineers call it as green oil.

Solder_mask

Solder mask applied on the PCB designed as a protection layer to avoid oxidation, corrosion and other environmental impacts when they leave production line. In addition, solder mask between solder pads also can help to prevent forming to solder bridge when assembly.

Below are some other functions of coating a layer solder mask:

  • Prevent physical line breaking of copper trace
  • Only weld in the area that must be soldered to avoid waste of soldering
  • Reduce copper pollution to soldering groove 
  • Prevent insulation deterioration and corrosion caused by dust, moisture and other external environmental factors 
  • With high insulation, so that the high-density circuit is possible

Part 2: What is Solder Paste?

Solder Paste also known as “Solder cream”, is a most important soldering material used in surface mount technology (SMT) process. Mainly function for soldering resistors, capacitors, ICs and other electronic components onto the PCB surface to form a permanent connection.

The solder particles are a mixture of solder formed by mixing solder powder, flux and other surfactants and thixotropic. Traditionally this used to be tin and lead, but with the legislation has been introduced around the world, to only use lead free solders. These may be made from a variety of mixtures, Best Technology commonly used is SAC305 which includes 96.5% tin, 0.5% copper and 3.0% silver, some manufacturers also use 99.7% tin and 0.3% copper, whereas there are other mixtures that include other metals including tin.

Due to the role of solder paste in assembly, solder paste storage is extremely important. However, solder paste got into drying during storing became a common problem faced by most PCBA manufacturers, so How to solve solder paste dry problem is premier.

Solder_paste

Part 3: The Difference Between Solder Mask and Solder Paste

  1. Solder mask is a formal part of PCB, but solder paste ONLY for PCB assembly.
  2. Solder mask is not allowed on the solder pads while solder paste can be printed on the solder pads openings.
  3. Solder mask is used for applying solder mask ink, but solder paste is used for applying paste.
  4. Solder mask has many available colors, but paste mask visually gray.
  5. Solder mask is coating during PCB fabrication, but solder paste is printing when PCB assembly.

With over 16 years in PCB industry, Best Technology is one of the most reliable PCB and PCBA supplier in Asia, we commit to provide high quality products with excellent service before and after sales, to take care our customers wholeheartedly, and to treat customers’ business as ours. At the same time, we keep learning and continually to improve ourselves so that we can catch up the latest technology trend and provide better and better service for our customers.

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“Eight” Safety Spacings You Must Know In PCB Design

Wednesday, December 7th, 2022

There are many places in the Printed Circuit Board Design that need to consider the safety spacing, here we summarized Eight Safety Spacings in total to show you what spacing we should pay attention to when designing, they can be separated into two categories, one is Electrical-Related Safety Spacing, and another is Non-Electrical-Related Safety Spacing.

Electrical-Related Safety Spacings

  • Wire Spacing

As far as the processing capability of the mainstream PCB manufacturer is concerned, the spacing between the wires shall not be less than 0.075mm. The minimum line distance refers to line to line, line to pad space.  From a production perspective, the larger the better, and the more common wire spacing is 0.25mm by far.

  • Diameter and Width of Pad

From the processing capability of mainstream PCB manufacturers, the minimum diameter shall not less than 0.15mm if the holes on pad requires mechanically drilled. If used laser drilling, then hole diameter must greater or equal than 0.10mm. At the same time, the tolerance of hole diameters varies slightly according to different substrates. Generally, it can be controlled within 0.05mm, and the minimum width of the pad should not be less than 0.2mm.

  • Spacing between Pad to Pad

The spacing between pads must be at least 0.2mm as far as the processing capacity of mainstream PCB manufacturers concerned.

  • Copper and Edge of the Board Spacing

The spacing between electronic copper and edge of the board should be no less than 0.30mm, and it can be set spacing rule on the “Design – Rules – Board outline” page.

If it requires a larger area of copper, it is generally needs to set 0.5mm as a retraction spacing from the edge of board. In the PCB design and manufacturing industries, engineers often shrink the large area of copper coating to the edge of the board by 20mil for mechanical considerations of the finished circuit board, or to avoid the occurrence of curling or electrical short circuit caused by the exposure of copper on the edge of the board, rather than coating whole copper to the edge of the board.

There are many methods to handle such shrink problems, such as drawing a keepout layer and then set a distance between copper and the keepout. As a professional PCB manufacturer that have rich experience over 16years, there is a much easy way to set different safety spacings for copper objects. For example, the safety spacing of the whole board set as 0.25mm, then we can set copper to 0.5mm, which can achieve a shrink distance of 0.5mm, and the dead copper that may cause in some devices also can be removed as well.

Non-Electrical-Related Safety Spacing

  • Width, Height and Spacing of Legends

We can’t make any changes during the processing of text legend film, except that the line width of legend with D-CODE less than 0.22mm (8.66mil) is enlarged to 0.22mm, that is, the line width of legends L=0.22mm (8.66mil). 

The width of the whole charact legends W=1.0mm, the height of the whole legends H=1.2mm, the spacing between the legends D=0.2mm. When the text is less than the above standard, the text legends after printing will be blurred.

  • Spacing between Via to Via

The spacing between vias to vias is preferably not less than 8mil.

  • Spacing between Legend to Pad

Legends/Silkscreens are not allowed on the pads, otherwise, the covered area can’t be tinned and which will affect the assembly process finally. Generally, manufacturer requires a 8mil space to convenient for silkscreen printing, but if your PCB is small and limited in area, it is barely acceptable to leave a 4 mil safety space.

If some legends accidentally over the pads in your design, Best Technology will remove or move to another area when get your approval to ensure good tinned.

Of course, design on a case-by-case situation.  Sometimes the screen printing is deliberately close to the pad, because when the two pads are very close, the screen printing in middle can effectively prevent the short circuit of the solder connection during soldering, and this is another case.

  • Mechanical 3D height and Horizontal Spacing

When mounting the components on the PCB surface, it is necessary to consider whether there will be conflicts with other mechanical structures in horizontal direction and spatial height.  Therefore, in the PCB design, the compatibility between components, finished products and product outer house and spatial structure should be fully considered, and the safety spacing should be reserved for each target object to ensure there is no conflicts occur in space.

In summary, there are many data and key points should be pay highly attention to while in PCB designing, Best Technology manufactures varies of good quality PCBs for our customers, so please do not hesitate to contact us when you have PCB design, we can help to evaluate it freely for you.

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Differences Between Immersion Gold and Gold Plating In PCB?

Wednesday, December 7th, 2022

With more and more extensive usage of Printed Circuit Boards, the IC become more and more integrated and IC pins on PCB are also more denser (such as 0603, 0402 spec ICs), which brings a big difficulty to SMT process. In addition, the shelf life of HASL board is very short, and Gold-plated board can solve such problems perfectly, that’s why it is common and popular to use gold board in high precision and ultra-small assembly process. Nowadays, there are two kinds of gold coating method in PCB industry – Immersion gold & Gold plating. To make you a sense of them, today we will simply introduce their definition and the differences between two of them.

Part 1: What is Immersion Gold (ENIG)

Immersion Gold also named as ENIG (Electroless Nickel/Immersion Gold) is generating a layer of coating by chemical REDOX reaction, is a kind of chemical nickel gold deposit surface finish during PCB manufacturing process. We can get a thicker layer of gold, but as its weak adhesion through immersion, it is also known as Soft Gold.

Part 2: What is Gold Plating

Gold plating is an another surface treatment of depositing a thin layer of gold on PCB surface by plating, the working principle is to dissolve nickel and gold (commonly known as “gold salt”) in the chemical potion, then immerse the circuit board in the electroplating cylinder and through the current on the copper foil surface of the PCB to generate a layer of gold plating. The gold particles attached to the PCB, as strong adhesion also known as “hard gold”. Gold plating is widely use in electronic products as its characteristics of hardness, excellent abrasion resistance and not easy to be oxidized. For example, the gold finger of flash driver in our computer is hard gold.

Part 3: The differences between Immersion Gold and Gold Plating

  • In generally, the gold thickness of immersion is thicker than plating, and immersion gold is golden yellow while gold plating is yellowish white, so just from appearance, most customers prefer like immersion gold.
  • Due to the crystal structures between them are different, immersion gold is easier to operate in SMT process, and won’t cause the poor soldering issue.
  • Immersion gold is softer than plating way, so if boards required gold fingers, it is always use plate-gold as its good wear resistance properties.
  • There is only nickel gold on the solder pad, so under the conductor skin effect, the signal transmission won’t be affected in copper layer.
  • Compared with gold plating, immersion gold has more denser crystal structure and is not easy to oxidation.
  • With the denser line width and space requirements, plating method is easily to cause short circuits, but since immersion gold board only has gold on solder pads, which won’t exist such issue.
  • The adhesive between solder mask and copper layer on circuit is stronger as there is only nickel gold on immersion board, so it is easier for engineers to make compensation when adjust line space.
  • Black-Pad won’t be happened to immersion board after assembly because it has good flatness than plating method.
  • Immersion gold is more economy than plating.

Best Technology is a professional PCB manufacturer with over 16 years experiences, and we have rich and mature technical to fabricate immersion gold and gold-plated boards. Warm welcome to contact us at sales@bestpcbs.com if you have any questions or RFQs about printed circuits, we are always online.

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A Guideline about Legend on Printed Circuit Board

Tuesday, November 29th, 2022

Printed circuit board is used to power up the electronic devices, and the legend on its surface been known as legend text or silkscreen text to be aim at providing vital information to electronic manufacturers or end users. This post is a guideline to help you understand what information we can gain from those legends and what we need to pay attention to when design them.

A brief introduction about PCB legend

Though a printed circuit board doesn’t require any legend/text to function technically, the text provides key information to end users to test, assemble and troubleshoot, and generally we can obtain following information from the legends:

  • Branding information

This includes manufacturer’s information, serial numbers, date code and other information, which prevents the copying of design.

  • Part number provided

Part numbers are added on the circuit boards to enable replacement or design evolution whenever needed.

  • Version of product

Sometimes versions were updated, and the legend is added on the circuits to identify the specific version and backtrack the date.

  • Reference of components indicators

This may feature components information such as indicators, orientations and other information.

  • Safety Precautions

These are warning signals that are added to protect users from electric shocks. A few examples of these may include grounding, high voltage, and so on.

  • Circuit Identification

Users and designers can identify circuit names from legends to understand testing points, ground points, component interconnect, so forth.

  • Polarity indicator for certain components

Some components such as diodes, LED chips, electrolytic capacitors require to a distinguish of polarity when assembly, text legends help to indicate the right polarity to ensure assembled correctly and perform functionality when reach to consumers.

  • Authentication indication

Silkscreen text shows the boards are authenticated or conforms to certain security certification, such as RoHS, 94V-0, UL…

  • Test points and troubleshooting assistants

Help to correctly perform testing including resistance measurement, voltage measurement, function testing and so forth.  In addition, text legend enables to troubleshoot while issues or debugs happened and repair is required.

  • Component outlines indicating where components should go

Legends provides a great help during assembly process, it helps the operator quickly find where each component should be, so it is recommended to add text legends when PCB need to be assembled.

General Parameters for PCB Legend in Best Technology

To understand the capabilities of legend printing of Best Technology, here we listing some general parameters for your reference:

  • Legend colors can be white, black, green, yellow or other colors depend on customer’s preferences.
  • Legend line width is range from 5mil to 7mil
  • Text height can set at 30mil
  • Maximum text width can be 17mil
  • Printing methods are screen printing, direct legend printing and Liquid photo imaging. (Direct legend printing is commonly used by far.)

Important factors need to be considered during designing

Although legends are easy to be printed, there are still some key points need to pay highly attention when you are designing.

  • Legend orientation: To maintain a good reading appearance for user, please make sure all legends throughout the board have a same orientation.
  • Choose a standard color and shapes for marking, this is a most economy way to save cost.
  • Avoid overlapping: Overlapping is one of the most common problems that manufacturer faced. Legend always be related to PCB layout, and components reference will be also designated when circuit board layout finished. So if the legend was overlapped, it must be moved to another place and that may cause component reference was located in a wrong position, so it is always recommend to double check all the legends, to make sure they are clear and in the correct position when the whole board layout was completed.
  • Do not place the silkscreen text on all four directions, this will lead to confusions when the circuit board is undergoing repair.
  • Leave a few mils space for some common potential printing errors, this will help manufacturer to reduce the possibility of errors.

Every PCB manufacturer has its unique style and pattern when it comes to legend printing, so working files confirmation plays an important role before circuit fabrication, Best Technology gives a great respect to the original files to our customers, we won’t start production until get approval of working files from customers, so please do not worry about it if you have such concerns. In addition, as a professional printed circuit board manufacturer in Asia, we are confident that we can provide you with high quality PCB, welcome to contact us if you have PCB needs.

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3M Epoxy Adhesive DP190-Gray & 3M Epoxy Adhesive DP190-Translucent

Friday, April 22nd, 2022

Both 3M Epoxy Adhesive DP190-Gray and 3M Epoxy Adhesive DP190-Translucent are a two-part epoxy adhesive that delivers exceptional performance with high shear and peel strength.

They can bond to a wide range of materials, such as metals, ceramics, wood, fiberboard, glass, rubber and many plastics. So, PCB is no exception. But what are the similarities and differences between them?

Similarities

  • Provide tough, strong bonds through high shear and peel strength.
  • Capable of bonding to a wide variety of different materials.
  • Deliver extended work-life, providing additional time for adjustment.
  • Exhibit good environmental aging properties, delivering long-term durability.

Differences

3M Epoxy Adhesive DP190-Gray has a moderately high modulus. With a 90-minute work-life, it reaches handling strength in approximately 10 hours and full cure in 7 days at room temperature.

Additionally, this epoxy adhesive has medium viscosity and self-leveling with a 1:1 mix ratio by volume. But its flexibility and elongation are moderate.

(3M Epoxy Adhesive DP190-Gray)

3M Epoxy Adhesive DP190-Translucent has a moderately low modulus. With an 80-minute work-life, it reaches handling strength in approximately 10 hours and full cure in 14 days at room temperature.

It has low viscosity and self-leveling with a 1:1 mix ratio by volume. Additionally, it features high flexibility and elongation.

3M Epoxy Adhesive DP190–Translucent

This is all about the similarities and differences between the 3M Epoxy Adhesive DP190-Gray and 3M Epoxy Adhesive DP190-Translucent. It is supposed that you have known about them.

But if you still have any questions about them or PCB, please feel free to contact us. Because at Best Technology, we are fully equipped to handle your PCB manufacturing requirements.

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Via Tented, Via Filled & Via Plugged

Monday, December 20th, 2021

Via Tented, Via Filled (filled with solder mask) & Via Plugged (Via In Pad – Conductive material or Non-Conductive material)

One of the most confused idea during our PCB design is the difference between Via Tenting, Via Filling and Via Plugging. Designers often get mixed up between them and fail to take full advantage of the process.

Today, let us discuss them, so that you can be confident in specifying your design requirements clearly when submitting PCB files to Best Technology before final manufacturing.

Via Tented

What is via?

A plated through hole (PTH) in a Printed Circuit Board that is used to provide electrical connection between a trace on one layer of the Printed Circuit Board to a trace on another layer. Since it is not used to mount component leads, it is generally a small hole and pad diameter.

A. Three methods and definitions of via processing

There are three methods for via processing: via hole opening & via hole cover oil & via hole plug oil

1. Through hole opening window: it is the tin on the solder ring of the via (the tin is exposed like a plug-in pad). The window is usually used to debug the measurement signal. The disadvantage is that it is easy to cause a short circuit.

2. Through hole cover oil: it is the welding ring of the through hole (via) covered with solder mask ink

3. Through hole plugging oil: refers to plugging the hole with ink.

Secondly, the inspection standards for a processing method

1. Through-hole opening window is like a plug-in pad, and the window is sprayed with tin. Inspection standard: tin can be tinned, and tin can be easily tinned.

2. The inspection standard of the via hole cover oil: it is not easy to tin in the patch.

3. Inspection criteria for via plug oil: First, it must be opaque, and it must be covered and blocked by ink.

Finally, we are talk for comparison and distinction between via hole cover oil and via hole plug oil:

1. Via plug oil This process is an important supplement to via plug oil, so generally high-quality boards will require via plug oil. And often many engineers who are just entering the industry are stupid and unclear. So how do you distinguish between the two?

2. The requirement of via hole cover oil is that the ring of the via hole must be covered with ink. The emphasis is to ensure the thickness and coverage of the ink on the edge of the hole. The key control is that the ring does not accept false copper exposure and orifice oil. Thin

3. Through hole plugging oil is the production of plug holes with ink inside the holes of the through holes. The emphasis is on the quality and density of the plug holes. After the holes are plugged, no light can be transmitted.

4. The method of plugging the via hole is to first fill the via hole with ink to block the via hole, so that the ink on the solder mask will not flow into the via hole, so as to achieve the situation that the via hole does not appear yellow. (If you have strict requirements and place an order for via hole cover oil, the cover oil is usually not full or yellowish, you can change it to via hole plug oil later). In addition, the smaller the vias are, the easier it is to plug them. The vias of the fortress oil are not easy to be too large (the circuit board proofing plugging oil is directly plugged with ink, and the printing tape is plugged. It is recommended that the vias that need to be plugged are designed to be <0.5mm. This is also free; no additional money is required).

If you have more question Via Tented, Via Filled& Via Plugged, warmly welcomed to contact Best Tech for more FR4 design service.

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A Brief introduction for different layers on Multilayer PCB

Friday, October 29th, 2021

When it comes to multilayer PCB, we know the multilayer PCB are consisted by many different layers. Do you know what’s the purpose for these layers?

Here I would like to give you a brief introduction for the functions of each layer on a Multilayer PCB design.

Mechanical layer: There may be one or several mechanical layers in a PCB depending on the design. There should be at least one mechanical layer as it shows the physical dimensions of the board. Generally, it used GM1, GM2 to name the file on the Gerber.

Solder paste layer: This is a material applied onto the PCB layers where components are mounted, mostly through soldering. It helps with the bonding of the solder with the component pin and improves the solder flow. PCB Assembly supplier will make stencil according to the solder paste layer on the Gerber.

Generally, it used GPS, GBS to name the file on the Gerber.

Solder mask layer: This layer is a mask or a protective coating applied onto the board to prevent damage and contamination. It is typically green in color; however, you can also choose other colors such as blue, black, white depending upon your requirements. Generally, it used GBS, GTS to name the file on the Gerber.

Ground planes and power planes: These are layers for copper, the ground and the power planes are connected to an onboard voltage point. Generally, it used GND, PWR to name the file on the Gerber.

Split planes: This is a modified version of power and ground planes; they are split in a manner that they can be connected to multiple voltage points or potentials.

Keep out layer: This layer is crucial as it defines the working boundary and keeps it separate from the outer mechanical layer. Generally, it used GKO to name the file on the Gerber.

Silkscreen layer: This is typically the text displayed on the boards through which you can identify components with their names. It is typically white in color when solder mask color is green, black, blue and red. But you can also choose other colors such depending upon your requirements. Generally it used GTO, GBO to name the file on the Gerber.

Routing layer: These layers help to interconnect the components. They can also be present on the top and bottom layers of the board.

Drilling Layer: This is the layer to show the drilling information of the PCB. Usually, it names DRL on the Gerber.

Once we understand the purpose of each layer for PCB, then understanding the construction of PCB becomes easy, no matter how complicated the board structure.

With over 15 years of PCB manufacturing experience, BEST Technology can meet different requests from customers no matter it is prototype or high-volume PCB.

Send us your request, let us to make the high-quality printed circuit boards for you.

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About the “heat” problem in PCB & MCPCB

Monday, October 18th, 2021

For high-power products, the concept of “heat” is often mentioned, which is especially important in high-power products. It not only determines the service life of the product, but also relates to whether the product can work properly.

We will explain the “heat” problem in circuit board design from three aspects: the generation of heat, the impact of heat on the product and the “heat” in the system layout.

1. Heat generation:

Heat generation in a system takes several paths:

1) Power consumption of the component itself

2) Efficiency of power conversion devices

3) High frequency signal conversion heating

4) Power consumption of contact resistance and wire resistance during signal transmission

2. Impact of fever on products

The operating temperature of components is generally below 80 degree, and the operating temperature of commonly used capacitors and resistors is generally controlled below 50 degree. If the temperature of the system is not controlled, the following conditions may occur:

1) The temperature rise will cause the working parameters of components to change, resulting in the unstable working performance of the whole system.

2) Temperature rise will accelerate the aging of components, affecting the accuracy and life of components.

3) Temperature rise will cause circuit board deformation and poor connection of components.

General heat dissipation components arrangement

3. “Hot” considerations in system layout

1) Selection and layout of the chassis: choose materials with good thermal conductivity, such as aluminum alloy

2) Black heat absorbing material is coated inside the shell to enhance the function of radiation heat absorption

3) The shell is closely combined with the components with high calorific value to conduct heat dissipation

4) A large number of heating components should be placed at the edge of the plate to shorten the heat transfer path. Heat-resistant components should be kept away from light sources.

5) In the design process, the appropriate wire width and copper thickness should be selected, and the influence of wiring density on the current-carrying capacity should also be considered. Copper foil should be filled in the gap of the board surface as far as possible for heat conduction. The heat conduction hole can help effectively heat dissipation and reduce local temperature.

In the design of circuit board, how to effectively control the temperature of the system is a problem that must be considered.

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